Modern navigation systems and other systems such as an Advanced Driver Assistance System (ADAS) rely on map data. Map data typically comprise point data indicative of geographic coordinates of certain geographic objects such as roads, railway lines, street addresses, rivers and special points of interest (such as hotels, restaurants and gas stations). For roads and other extended geographic objects discontinuous point data are not always a suitable base for the implementation of required processing or display functions. It has thus been proposed to represent the course of an extended geometric object by a continuous sequence of linear geometric elements such as circular arcs, line segments and clothoids.
DE 101 14 412 C1 teaches a technique for converting road points into a sequence of clothoids that describe a continuous course of a road. DE 10 2005 024 558 A1 describes an approach for deciding for a set of two adjacent road points whether to select a line, a circular arc or a clothoid as the geometric element for locally describing the course of the road between these two road points. The information about the individual geometric elements thus determined is used for calculating a maximum vehicle speed per geometric element.